1. Field of the Invention
This invention is generally related to a composition useful for straightening hair or providing a permanent wave in hair and, more particularly, to a composition which can safely and effectively straighten or permanently wave virgin (not previously treated) Afro-American hair.
2. Description of the Prior Art
Most commercially available formulations for straightening or waving "Afro-American" or "Black" hair utilize harsh hydroxide chemicals (sodium, potassium, calcium and lithium hydroxides). The highly alkaline conditions (pH 12-14) of these products cause hair swelling and disruption of disulfide bonds followed by the formation of carbon-sulfur bonds. The high pH of the products causes the partial dissolution of the intercellular matrix in the hair cuticle, rendering the hair brittle and fragile. Under the conditions of pH 12-14, some hydrolysis of the polypeptide chains in the hair protein can also occur. Prolonged exposure of hair to a strong alkali weakens and can eventually dissolve the hair.
U.S. Pat. No. 5,148,822 to Akhtar et al. discloses a hair treatment method employed with traditional high alkaline relaxers. Rather than washing the relaxer from the hair with an "acid wash" (shampoo or rinse of acidic pH used to neutralize the relaxer), Akhtar et al. disclose adding a texturing or strengthening agent, preferably a quaternary ammonium derivative of hydrolyzed collagen protein, to the hair which has a pH between 8 and 11. The treatment method is said to enhance and sustain the cation receptivity of alkali-treated hair while shampoo resistant benefits are provided. Akhtar et al. list morpholine as an exemplary lower alkyl organic base which can be used to adjust the pH of the composition which includes the texturing and strengthening agent. No particular benefits with regard to hair straightening attributable to morpholine are disclosed.
U.S. Pat. No. 3,583,408 to Wall discloses treating hair with both a reducing agent and a vinylic monomer containing acid groups. The vinylic monomer is polymerized via addition-type polymerization during the process. The long chain polymers formed in the hair from the vinylic monomer provide a chemical backbone for strengthening the hair. The Wall patent also discloses the use of sodium bisulfite as a reducing agent responsible for breaking the disulfide bonds between the keratin molecules of the hair, and the use of urea as a swelling agent to enhance the penetration of the active ingredients into the hair fibers. Wall suggests having the sodium bisulfite constitute 1.5 to 10 percent by weight of the waving lotion.